A US-Russian ceasefire deal for Syria was on the brink of collapse after a week of mishaps and setbacks that exposed the fragility of the plan.
The ceasefire is premised on a series of trust-building exercises that were intended to culminate tomorrow in the launch of preparations between the United States and Russia for joint airstrikes against terrorist groups in Syria.
Instead, an errant strike yesterday by the US-led coalition against Isis (Islamic State) that mistakenly killed dozens of Syrian government soldiers has exposed the deficit of trust between the two powers.
Whether US warplanes conducted the attack is in question. The US-led coalition is made up of 67 countries, more than a dozen of which carry out airstrikes against the militants.
The Defence Department of Australia, which is among the nations contributing to the effort, acknowledged in a statement that its warplanes had participated in a strike in Deir al-Zour, the eastern Syrian city where the attack occurred, on a front line between the Syrian Army and Isis that has changed hands many times.